JP3803147B2 - Drilling pressure control device for drilling device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a striking pressure control device for a drilling device having a striking mechanism used for excavation of a rock mass.
[0002]
[Prior art]
In general, a drilling device used for rock excavation is provided with a hydraulically driven striking mechanism, a rotating mechanism, and a feed mechanism. The striking mechanism strikes the drilling rod, and the rotating mechanism drills. A rotation is given to the hole rod, and a feed mechanism feeds the hole rod to make a hole in the rock.
[0003]
The striking mechanism has a characteristic that when the flow rate increases, the striking pressure increases and the striking force increases, and when the flow rate decreases, the striking pressure decreases and the striking force decreases.
With the development of hydraulic technology in recent years, automatic control incorporating electrical control technology has been put into practical use in the drilling device, but because of the large number of parts and high cost, maintenance is troublesome. In many cases, the control by is required.
[0004]
In a conventional drilling device controlled only by hydraulic pressure, the striking mechanism, the rotating mechanism, and the feed mechanism are driven by a hydraulic circuit as shown in FIG.
In this drilling device, the striking mechanism 71, the rotating mechanism 72, and the feed mechanism 73 are passed from the hydraulic source through the striking hydraulic fluid path 74, the rotating forward rotating fluid path 75, and the feeding forward fluid path 76 when drilling. Each is supplied with the necessary pressure oil.
[0005]
The striking hydraulic fluid passage 74 is provided with a manual striking hydraulic pressure switching valve 82, which controls the switching between the striking pressure during stroking and the striking pressure during normal drilling by adjusting the flow rate by operating the lever. .
[0006]
In addition, a relief valve 83 and a pilot switching valve 84 are provided between the striking hydraulic fluid passage 74 and the striking return fluid passage 77, and the pilot port of the pilot switching valve 84 is connected to the rotation normal rotation fluid passage 75. Accordingly, the relief pressure 83 is actuated by increasing the rotational pressure to regulate the striking pressure.
[0007]
The rotation pressure of the rotating mechanism varies depending on the condition of the drilled rock. When the drilling state is deteriorated and the rotational resistance is increased, the rotational pressure is increased, so that the impact pressure is reduced and the impact force is reduced.
[0008]
[Problems to be solved by the invention]
However, in recent years, as the performance of the drilling device has improved and the striking force of the striking mechanism has increased, there has been a concern about an increase in consumable damage due to striking.
[0009]
The striking force has an adverse effect on consumables when the thrust of the feed mechanism is insufficient and the striking force is not effectively consumed by the drilling of the rock mass. For this reason, the appropriate striking pressure was not controlled.
[0010]
The present invention solves the above-mentioned problem in controlling the striking pressure of the drilling device, and the striking force of the striking mechanism is reduced when the thrust of the feed mechanism is small and the striking force is not sufficiently consumed by the rock drilling holes. When the thrust of the feed mechanism is large and the striking force is sufficiently consumed in the drilling hole of the rock, the striking pressure is controlled so that the striking force becomes large, and the drilling device that prevents consumables from being damaged is used. An object is to provide a striking pressure control device.
[0011]
[Means for Solving the Problems]
In the drilling pressure control device for a drilling device of the present invention, in the drilling device provided with a hydraulically driven hitting mechanism, a rotating mechanism, and a feed mechanism, the hitting hydraulic fluid path and the hitting return oil path of the hitting mechanism are provided. Are connected by a bypass oil passage, and a flow rate control means for reducing the flow rate of the bypass oil passage by increasing the pressure of the feed forward oil passage of the feed mechanism is provided in the middle of the bypass oil passage.
[0012]
During drilling, the striking mechanism, rotating mechanism, and feed mechanism are each supplied with the necessary pressure oil from the hydraulic source via the striking hydraulic fluid passage, the forward rotating fluid passage, and the forward feed fluid passage. The
[0013]
When the thrust of the feed mechanism is small and the striking force is not sufficiently consumed in the drill hole in the rock, the pressure of the forward oil passage for feed is small, so the flow control means increases the flow rate of the bypass oil passage and hits the striking mechanism. Decrease the impact force by decreasing the flow rate of the hydraulic fluid passage and decreasing the impact pressure.
[0014]
When the thrust of the feed mechanism is increased and the striking force is sufficiently consumed in the drill hole in the rock mass, the flow control means reduces the flow rate of the bypass oil passage because the pressure of the forward oil passage for feed has increased. Thus, the flow rate of the hydraulic fluid passage for impact of the impact mechanism is increased, and the impact pressure is increased to increase the impact force.
Controlling the striking pressure in this way prevents damage to the consumables of the drilling device.
[0015]
Further, in a drilling device equipped with a hydraulically driven impact mechanism, a rotation mechanism, and a feed mechanism, the feed return oil passage of the feed mechanism is connected to the normal rotation oil passage of the rotation mechanism, and the impact mechanism strikes. The hydraulic oil path for impact and the return oil path for impact are connected by a bypass oil path, and the bypass oil is increased by increasing or decreasing the pressure difference between the forward oil path for feeding and the forward rotating oil path for rotation in the middle of the bypass oil path. If a flow control means is provided to reduce the flow rate of the passage, the thrust of the feed mechanism is given by the pressure difference between the feed forward oil passage and the forward rotation oil passage of the feed mechanism, and the drilling state deteriorates. When the rotational resistance increases, the pressure in the forward rotation oil passage increases, and the pressure difference between the feed forward oil passage and the rotation forward oil passage of the feed mechanism becomes smaller and the thrust is reduced. The
[0016]
Here, when the thrust of the feed mechanism is small and the striking force is not sufficiently consumed by the drill hole in the rock, the pressure difference between the feed forward oil passage and the rotation forward oil passage of the feed mechanism is reduced. Therefore, the flow rate control means increases the flow rate of the bypass oil passage to decrease the flow rate of the impact hydraulic fluid passage of the impact mechanism, and reduces the impact pressure to reduce the impact force.
[0017]
When the thrust of the feed mechanism is large and the striking force is sufficiently consumed in the drill hole in the rock mass, the pressure difference between the feed forward oil passage and the forward rotation oil passage of the feed mechanism increases, so the flow rate The control means decreases the flow rate of the bypass oil passage to increase the flow rate of the impact hydraulic fluid passage of the impact mechanism, and increases the impact pressure to increase the impact force.
[0018]
If the flow control means can be operated so as to reduce the flow rate of the bypass oil passage only when a predetermined pressure is generated in the forward rotation oil passage, when the work without rotation is performed by connecting and collecting the drilling rod, etc. The flow rate control means can be stopped so as not to operate.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a hydraulic circuit diagram of an impact pressure control device for a drilling device showing an embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing an example of a flow rate control means, and FIGS. 3 to 5 are operating states of a control spool FIG. 6 is a graph showing the relationship between the control spool movement amount and the control spool pushing force, and FIG. 7 is a graph showing the relationship between the control spool movement amount and the orifice opening area.
[0020]
The drilling device includes an impact mechanism 1, a rotation mechanism 2, and a feed mechanism 3 that are driven by hydraulic pressure. The impact mechanism 1, the rotation mechanism 2, and the feed mechanism 3 are connected to the hydraulic source 10 when drilling. Necessary pressure oil is supplied through the hydraulic oil passage 4 for impact, the forward rotation oil passage 5 for rotation, and the forward oil passage 6 for feed. Therefore, the striking mechanism 1 strikes the drilling rod, the rotation mechanism 2 rotates the drilling rod, and the feed mechanism 3 thrusts the drilling rod to drill the rock. . The return oil from the striking mechanism 1, the rotation mechanism 2, and the feed mechanism 3 returns to the tank 11 from the striking return oil path 7, the rotation return oil path 8, and the feed return oil path 9, respectively.
[0021]
The striking hydraulic fluid passage 4 is provided with a manual striking hydraulic pressure switching valve 12, and controls the switching between the striking pressure during stroking and the striking pressure during normal drilling by adjusting the flow rate by operating the lever. .
[0022]
A bypass oil passage 13 is connected between the striking hydraulic fluid passage 4 and the striking return fluid passage 7 of the striking mechanism 1, and a flow rate control means 20 is provided in the middle of the bypass oil passage 13. Yes.
[0023]
As shown in FIG. 2, the flow rate control means 20 is provided with a control spool 22 in a body 21 so as to be movable left and right. On the inner periphery of the body 21, a high pressure oil chamber is separated by a predetermined distance from side to side. 23 and a low pressure oil chamber 24 are formed, the high pressure oil chamber 23 communicates with the impact hydraulic fluid passage 4 via the high pressure port PH, and the low pressure oil chamber 24 communicates with the return fluid passage 7 for impact via the low pressure port T. Communicate. The control spool 22 includes a communication oil passage 25 therein, an orifice 26 for communicating the high pressure oil chamber 23 and the communication oil passage 25, and an oil communicating the communication oil passage 25 and the low pressure oil chamber 24. A plurality of holes 27 are disposed with their positions shifted in the left-right direction.
[0024]
A control oil chamber 33 is formed at the left end of the control spool 22, and the control oil chamber 33 communicates with the feed forward oil passage 6 via the control port FF.
A spring 28 that pushes the control spool 22 to the left is mounted on the right side of the control spool 22. The spring 28 is attached between a spring seat 29 that contacts the right end of the control spool 22 and a spring case 30 screwed to the right end of the body 21, and is pressed by a spring adjusting screw 31 provided on the spring case 30. You can adjust the power. The spring adjusting screw 31 is fixed by a lock nut 32.
[0025]
An oil groove 34 is formed in a cross shape on the right end surface of the control spool 22, and a moving speed restricting throttle 35 communicating with the oil groove 34 is provided in the spring seat 29, and between the spring seat 29 and the spring case 30. The spring oil chamber 36 formed in the communication with the striking return oil passage 7 through the movement speed regulating restriction 35, the oil groove 34, and the spring port SP. The movement speed restriction aperture 35 prevents chattering when the control spool 22 moves.
[0026]
In the drilling operation, the striking mechanism 1, the rotating mechanism 2, and the feeding mechanism 3 are respectively supplied from the hydraulic source 10 through the striking hydraulic fluid path 4, the rotating forward rotating oil path 5, and the feeding forward oil path 6. Necessary pressure oil is supplied.
[0027]
In the flow rate control means 20, the control spool 22 is initially in the position shown in FIG. 2, and the pressure oil supplied to the striking hydraulic fluid passage 4 is partially connected to the orifice 26 from the high pressure port PH as shown in FIG. Since it flows to the low pressure port T through the passage 25 and the oil hole 27 and returns to the tank 11 from the bypass hydraulic path 13 through the hitting return oil path 7, the striking force of the striking mechanism 1 is reduced.
[0028]
When the tip of the drilling device rod is pressed against the rock, the thrust of the feed mechanism 3 becomes large, and the pressure in the feed forward oil passage 6 exceeds a predetermined pressure, the pressure in the control chamber 33 of the flow rate control means 20 increases. Thus, the control spool 22 starts moving rightward from the state shown in FIG. As shown in FIG. 6, the movement amount of the control spool 22 increases or decreases linearly with respect to the control spool pressing force. The pressure at the start of movement can be adjusted with the spring adjustment screw 31. The rate of change of the movement amount with respect to the change of the pushing force can be changed by changing the characteristics of the spring 28.
[0029]
When the control spool 22 moves to the right, the right orifice 26 is closed as shown in FIG. 4, and the orifice opening area is reduced as shown in FIG. Accordingly, the amount of oil flowing from the high pressure port PH to the low pressure port T via the orifice 26, the communication passage 25, and the oil hole 27 is reduced, and the flow rate of the pressure oil supplied from the impact hydraulic fluid path 4 to the impact mechanism 1 is increased. Therefore, in the striking mechanism 1, the striking pressure is gradually increased as the pressure in the feed forward oil passage 6 increases.
[0030]
When the thrust of the feed mechanism 3 is increased and the striking force is sufficiently consumed in the drilling hole of the rock, the pressure in the feed forward oil passage 6 further increases, and as shown in FIG. The 20 control spools 22 move to the right stroke end. In this state, all the orifices 26 are closed, and no pressure oil flows into the bypass oil passage 13, so that the flow rate of the hydraulic fluid passage 4 for the impact mechanism 1 is maximized and the impact pressure of the impact mechanism 1 is increased. Let the impact strength be maximized.
[0031]
When the thrust of the feed mechanism 1 is reduced and the striking force is not sufficiently consumed in the drill hole in the rock, the pressure in the feed forward oil passage 6 is reduced. By increasing the flow rate, the flow rate of the hydraulic fluid passage 4 for the impact of the impact mechanism 1 is decreased, and the impact pressure is reduced by reducing the impact pressure.
[0032]
Controlling the striking pressure in this way prevents damage to the consumables of the drilling device.
FIG. 8 is a hydraulic circuit diagram of a striking pressure control device for a drilling device according to another embodiment of the present invention.
[0033]
Here, the feed return oil passage 9 of the feed mechanism 1 is connected to the rotation normal rotation oil passage 5 of the rotation mechanism 2, and the spring port SP of the flow rate control means 20 is the rotation normal rotation of the rotation mechanism 2. It is connected to the oil passage 5. Other configurations are the same as those in FIG.
[0034]
The thrust of the feed mechanism 3 in this case is shown by the following equation.
F = A (P _FF −kP _RF )
here,
F: Thrust A: Output constant k: Area constant P _FF : Feed forward oil passage pressure P _RF : When a hydraulic motor is used for the pressure feed mechanism 3 of the rotating forward oil passage,
k = 1,
F = A (P _FF −P _RF )
It becomes.
[0035]
In this case, the thrust F of the feed mechanism 3 is determined by the pressure difference between the feed forward oil passage 6 and the rotation forward oil passage 5.
Since the control port FF of the flow rate control means 20 is connected to the forward forward oil passage 6 of the feed mechanism 3 and the spring port SP is connected to the forward normal oil passage 5 of the rotary mechanism 2, the control spool 22 is also fed. It moves with the pushing force generated by the pressure difference between the forward oil passage 6 for rotation and the forward rotation oil passage 5 for rotation.
[0036]
Therefore, it is possible to control so that the striking pressure is lowered when the pressure of the feed forward oil passage 6 is low due to a countersink hole or the like, and the striking pressure is gradually increased as the pressure of the feed forward oil passage 6 increases. Instead, when the drilling state deteriorates and the rotation resistance increases, the pressure in the forward rotation oil passage 5 increases, and the feed forward oil passage 6 and the forward rotation oil passage 5 of the feed mechanism 3 Since the pressure difference is reduced, the thrust is reduced and the impact pressure is also reduced.
[0037]
When a hydraulic cylinder is used for the feed mechanism 3,
k = Rod side pressure receiving area / Cylinder side pressure receiving area, and A can be calculated by the cylinder side pressure receiving area.
[0038]
This case can be dealt with by adjusting the spring force of the flow rate control means 20 and changing the machining of the orifice 26, but it is preferable to use a flow rate control means 20 as shown in FIG.
[0039]
In this flow rate control means 20, a sub-piston 37 is provided between the control spool 22 and the control hydraulic chamber 33, and the pressure receiving area of the control spool 22 on the spring oil chamber 36 side and the control hydraulic chamber 33 of the sub-piston 37. The ratio of the pressure receiving area on the side is set to be equal to the ratio of the rod side pressure receiving area and the cylinder side pressure receiving area of the feed mechanism 3. By using this flow rate control means 20, the same control as in the case of k = 1 can be performed.
[0040]
FIG. 10 is a longitudinal sectional view showing an example of the flow rate control means used in the invention of claim 3.
The flow rate control means 20 is provided with a pilot piston 41 that is movable to the left and right between the high pressure port PH and the high pressure oil chamber 23, and this pilot piston 41 is always provided by a pilot spring 42 provided on the left side of the body 21. The high pressure port PH and the high pressure oil chamber 23 are held at a position where the communication is blocked. A pilot oil chamber 43 communicating with the spring port SP is formed at the right end of the pilot piston 41, and the pilot piston 41 moves to the left by the pressure of the spring port SP so that the high pressure port PH and the high pressure oil chamber 23 are connected. Communicate.
[0041]
In the flow rate control unit 20, the spring port SP is connected to the normal rotation oil passage 5 for rotation of the rotation mechanism 2. Here, the flow rate control means 20 connects the high-pressure port PH and the high-pressure oil chamber 23 only when a predetermined pressure is generated in the normal rotation oil passage 5 for rotation, and therefore bypasses only when the rotation mechanism 2 is operating. The impact pressure is controlled by decreasing the flow rate of the oil passage 13.
[0042]
Therefore, the impact pressure can be maximized when performing operations that do not involve rotation, such as connection and recovery of drilling rods.
[0043]
【The invention's effect】
As described above, the striking pressure control device for a drilling device according to the present invention is a drilling device provided with a hydraulically driven striking mechanism, a rotation mechanism, and a feed mechanism. By connecting a return oil passage for striking with a bypass oil passage, and providing a flow rate control means for reducing the flow rate of the bypass oil passage by increasing the pressure of the forward oil passage for feeding of the feed mechanism in the middle of the bypass oil passage, The striking force is small when the thrust of the feed mechanism is small and the striking force is not sufficiently consumed by the rock drilling hole, and the striking force is small when the thrust of the feeding mechanism is large and the striking force is sufficiently consumed by the rock drilling hole. It is possible to prevent the consumables from being damaged by controlling the striking pressure so as to increase.
[0044]
Further, in a drilling device equipped with a hydraulically driven impact mechanism, a rotation mechanism, and a feed mechanism, the feed return oil passage of the feed mechanism is connected to the normal rotation oil passage of the rotation mechanism, and the impact mechanism strikes. The hydraulic oil path for impact and the return oil path for impact are connected by a bypass oil path, and the bypass oil is increased by increasing or decreasing the pressure difference between the forward oil path for feeding and the forward rotating oil path for rotation in the middle of the bypass oil path. By providing a flow rate control means to reduce the flow rate of the road, when the drilling state deteriorates and the rotation resistance increases, the thrust is controlled to be small, and the thrust of the feed mechanism is small and the striking force is sufficient The striking force is low so that the striking force is small when it is not consumed by the drill hole in the rock, and the thrust of the feed mechanism is large and the striking force is large when the striking force is sufficiently consumed by the rock hole. Control and prevent damage to consumables Kill.
[0045]
Furthermore, by enabling the flow rate control means to reduce the flow rate of the bypass oil passage only when a predetermined pressure is generated in the normal rotation oil passage for rotation, work that does not involve rotation due to connection and recovery of the drilling rod, etc. When performing, it can be stopped so that a flow control means does not operate.
[Brief description of the drawings]
FIG. 1 is a hydraulic circuit diagram of a striking pressure control device for a drilling device according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of a flow control means.
FIG. 3 is an explanatory diagram of an operating state of a control spool.
FIG. 4 is an explanatory diagram of an operating state of a control spool.
FIG. 5 is an explanatory diagram of an operating state of a control spool.
FIG. 6 is a graph showing a relationship between a control spool movement amount and a control spool pressing force.
FIG. 7 is a graph showing the relationship between the amount of control spool movement and the orifice opening area.
FIG. 8 is a hydraulic circuit diagram of a striking pressure control device for a drilling device according to another embodiment of the present invention.
FIG. 9 is a longitudinal sectional view of the flow rate control means.
FIG. 10 is a longitudinal sectional view of the flow rate control means.
FIG. 11 is a hydraulic circuit diagram of a conventional drilling device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Blowing mechanism 2 Rotating mechanism 3 Feeding mechanism 4 Blowing hydraulic oil path 5 Rotating forward oil path 6 Feeding forward oil path 7 Blowing return oil path 8 Rotating return oil path 9 Feeding return oil path 10 Hydraulic source 11 Tank 12 Blowing hydraulic pressure switching valve 13 Bypass oil passage 20 Flow rate control means 21 Body 22 Control spool 23 High pressure oil chamber 24 Low pressure oil chamber 25 Connection passage 26 Orifice 27 Oil hole 28 Spring 33 Control oil chamber 34 Oil groove 35 Movement speed control throttle 36 Spring oil chamber 37 Sub piston 41 Pilot piston 42 Pilot spring 43 Pilot oil chamber FF Control port PH High pressure port SP Spring port T Low pressure port

Claims (3)

In a drilling device equipped with a hydraulically driven striking mechanism, a rotating mechanism, and a feed mechanism, the striking mechanism hydraulic fluid passage and the striking return fluid passage are connected by a bypass oil passage, and the middle of the bypass oil passage A striking pressure control device for a drilling device, further comprising flow rate control means for reducing the flow rate of the bypass oil passage by increasing the pressure of the feed forward oil passage of the feed mechanism. In a drilling device equipped with a hydraulically driven striking mechanism, a rotating mechanism, and a feeding mechanism, the feeding return oil path of the feeding mechanism is connected to the normal rotating oil path for rotation of the rotating mechanism, and the striking mechanism is operated for hitting. The oil passage and the return oil passage for impact are connected by a bypass oil passage, and in the middle of the bypass oil passage, the pressure difference between the forward oil passage for feeding and the normal oil passage for rotation of the feeding mechanism is increased. A striking pressure control device for a drilling device, characterized in that a flow rate control means for reducing the flow rate is provided. 3. The striking pressure control of the drilling device according to claim 1 or 2, wherein the flow rate control means is operable to decrease the flow rate of the bypass oil passage only when a predetermined pressure is generated in the normal rotation oil passage for rotation. apparatus.

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